Process of burning coal.



No. 898,134. PATENTED SEPT. s, 1908.

H. A. POPPENHUSEN & J. HARRINGTON.

PROCESS OF BURNING GOAL.

APPLICATION FILED JULY 17, 1907.

.3 SHEETS-SHEET 1.

No. 898,134. PATENTED SEPT. 8, 1908.

H. A. POPPBNHUSEN & J. HARRINGTON.

PROCESS OF- BURNING GOAL.

APPLICATION FILED JULY 17, 1907.

3 SHEETS-SHEBT 2.

LQLfiiessar No. 898,134. PATBNTED SEPT. a, 1908. 11. A. POPPBNHUSEN & J.HARRINGTON.

PROCESS OF BURNING GOAL.

APPLICATION FILED JULY 17, 1907.

3 SHEETS-SHEET 3.

UNITED sTATEs PATENT OFFICE.

HERMAN A. POPPEFHUSEN, OF EVANSTON, AND JOSEPH HARRINGTON, OF CHICAGO,

ILLINOIS.

PROCESS OF BURNING COAL.

Specification of Letters Patent.

Patented Sept. 8, 1908.

Application filed July 17, 1907. Serial No. 384,286.

T 0 all whom it may concern:

-Be it known that we, HERMAN A. PoPPEN- HUSEN andJosEPH HARRINGTON,citizens of the United States, and residents of Evanston and Chicago,respectively, in the county of Cook and State of Illinois, have inventedcertain new and useful Improvements in Processes of Burning Coal; and wedo hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings,and to the letters of reference marked thereon, which form a part ofthis specification.

This invention relates to an improved rocess or method of burning fuelin boi or or like furnaces of that kind in which fuel fed to the furnaceis continuously advanced or moved in a horizontally disposed layer alongor through the combustion chamber of the furnace during the progress ofcombustion.

The process or method constituting our invention consists generally insubjecting the coal or like fuel to a coking operation, without aerationor the su ply of air thereto for combustion, while suc fuel is being a'dvanccd in a continuous layer, subjecting the advancing layer during thecoking operation to a mechanical agitation to prevent caking orsolidification of the layer during such coking operation and after thecompletion of the coking operation continuin the advanced movement ofthe layer, wifiiout any mixing of the fuel constituting the layer and insuch manner as to maintain the upper art or surface portion of the layerand the ower part or bottom of the layer in the same relation that theyoccupied during the coking operation, and during such continuous advanceof the layer after completion of the coking operation, admitting air tothe layer for effecting combustion of the fuel during the remainder ofits travel or advance movement. Our process or method also includes thedeflecting or directing of all of the products of combustion arisingfrom the burning of the fuel during the second or combustion period,into contact with or "over the portion of the moving layer which isbeingsubjected to the coking operation, for the purpose of effecting thecoking thereof.

Our process or method may be better understood by reference to theaccompanying drawings in which is illustrated, in two different forms,apparatus adapted for carrying out our said process or method.

In said drawingsz Figure 1 is a view in central vertical section of aform of furnace adapted for carrying out our invention. Fig. 2 is adetail elevation of the transverse fuel supporting plates at the forwardend of the furnace, as seen from the front of the furnace. Fig. 3 is asectional view similar to Fig. 1 showingamodified form of constructionof the furnace. Fig. 4 is adetail elevation of a portion of the inclinedfuel supporting bars shown in Fig. 3, as-seen from the front of thefurnace. view showing three'of the inclined fuel supporting bars of Fig.3 and the actuating devices therefor. Fig. 6 is a detail plan section,taken on line 6-6 of Fig 3.

. As shown in the accompanyin drawings, A designates the front wall of t1e furnace, and B' the bridge Wall thereof.

C indicates a fuel hopper located on the front wall of the furnace inconnection with the fuel inlet or feed opening a thereof.

D indicates an endless traveling or chain grate of that class which ismoved or driven y'suitable actuating devices in such manner that theupper lap of the grate moves inwardly or from the'feed opening towardsthe bridge Wall of the furnace; said upper lap being substantiallyhorizontal.

E indicates a boiler, shown in said figures as a water tube boiler,having a front header E and a plurality of Water tubes 6 which extenddownwardly and rearwardly from said header.

F indicates a deflecting arch 0r artition which extends from the bridgewal B forwardly over the grate to a point near the front wall A of thefurnace, a space being left between the forward edge of said partitionand the front wall, which space constitutes the outlet 0 )ening for theupward or outward passage of t e products of combustion. Said ridge wallB is extended upwardly past the top surface of the grate and joins therear margin of said deflecting arch or partition.

G is a wall, of fire brick or like refractory material, which is builtagainst the front Wall A of the furnace above the feed opening, toprotect said front wall, and H is an arch which extends rearwardly fromthe top of the Fig. 5 is a detail wall G and forms a rotection for thefront header E of the boi er said parts being ar ranged to afford spacefor the passage of products of combustion around the forward edge of thesaid deflecting partition F on their way to the stack or exit flue ofthe furnace. As shown in Figs. 1 and 3, the said arch or partition F isinclined upwardly and forwardly from its rear end at which it is joinedto the bridge wall, but itneed not necessarily be so inclined. At theforward end of and above the chain grate D, in position to receive thefuel discharged from the feed hopper C, is an inclined fuel sup )ortarranged at an angle corresponding su stantially with the angle whichwill be assumed by the upper surface of a layer of coal resting thereonunder the action of gravity. Said inclined fuel sup )ort is providedwith means for agitating the layer of coal resting thereon in suchmanner as to aid the downward movement thereof and to prevent the samefrom caking or becoming solidified during the coking operation, whichtakes place when the coal is passingover said support, without stirringthe fuel or disturbing the relation between the surface portion and theunder portion of the coal in the layer, which relation remains thesamethroughout the operation or during the entire movement of the layerthrough the furnace.

In the construction shown in Figs. 1 and 2, said inclined sup ort isformed by means of three transverse y extending, inclined and overlappedmetal plates I I I Said plates are arranged with the upper ed e of theuppermost plate I adjacent to the ower edge of the bottom wall C ofthefeed hopper C, and with the lower edges of said upper plate I and theintermediate plate I overlapping the adjacent plates below them. Thelower margins of said plates I I I are shown as deflected downwardly soas to form a series of transversely extending ledges or shoulders in thesup orting surface formed by the said plates. Sai ledges or shouldersconstitute means to aid in agitating or breaking up the layer of fuelresting on the plate becoming baked into a solid mass by the action ofthe coking heat to which it is subjected. The said plates I I I aremovably supported in such manner that their lower edges may beoscillated or vibrated for the purpose of aiding in the downwardmovement of the layer of coal and to prevent the caking of said layer.As shown in said Figs. 1 and 2, the said plates are attached to andsupported upon horizontal rock-shafts J J J 2 which are mounted inbearings at their ends and afford oscillatory supports for theindividual plates. Devices are provided for giving oscillatory movementto said rock-shafts which, as shown in Figs. 1 and 2, is constructed asfollows: The intermediate rock-shaft J is provided with forwardlyextending horizontal arms 7' j, the outer ends of which are connectedwith uprig'l'itrods j which are attached at their lower ends tococentric straps j engaging eccentrics k I mounted on a transverselyarranged horizontal rotative shaft K. By the turning of said shaft K theeccentrics 7c 7r act through the rods y" y" to giveoscillatory movementto the arms j, which oscillatory movement is transmitted to therock-shaft J and the fuel supporting plate I attached to saidrock-shaft. Oscillatory movement is given to the lowermost rock-shaft Jand the lowermost su porting plate I by connections between t erock-shafts J and J", consisting, in the instance shown, of rigid,radial arms 1' j on said rock-shafts, which arms are connected with eachother by means of connecting rods or links j f. In the constructionshown in the drawing, the uppermost rock-shaftJ and the supporting plateI are not directly moved or actuated but a certain amount of oscillatorymovement is given thereto by means of contact of the lower edge of saidplate I with the upper portion of the oscillating plate I on which itrests.

From the construction described in the plates I I I", it will be seenthat the lower margins of said plates are given a vibratory or shakingmovement tending to aid or facilitate the downward movement of the layerof coal resting thereon. It will also be observed that the resence ofthe transfer ledges or shoulders ormed by the lower marginal arts ofsaid plates in connection with the vibratory movement given to saidlowermost margins of the plates will have the effect of agitating thedownwardly moving layer of fuel resting on said plates in such manner asto break u the same or prevent it becoming solidified into a continuousmass by the action of the coking heat to which it is subjected and thatthe breaking up or disintegration of the mass takes place withoutdisturbing the layer to such extent as to result in the turning over,mixing u or the imparting of a rolling motion to tie fragmentsconstituting the mass.

In the operation of the fuel supporting means consisting of thesupporting plates I I and I and the horizontal traveling grate D, fuelwill be fed from the feed hopper C in a layer of uniform thickness andthe layer of fuel thus discharged upon the inclined supporting surfaceformed by said plates will rest thereon with its surface inclinedsubstantially at the angle at which the coal will naturally rest underthe action of gravity; the mass -or layer on said su porting surfacebeing sustained thereon by t 1e contact of the lower part of said layerwith the traveling grate which, in its rearward movement, carriesrearwardly the coal from the lower part of said inclined layer, therebypermitting the latter to descend or slide downwardly along or over saidinclined surface at a rate of speed the fusible constituents thereof.

depending upon the rate of traveling of the chain grate. The layer offuel passes from the inclined surface to the traveling grate withouthaving the upper and lower portions of the layer mixed with each other.In other words, the top portion of the layer on the inclined surfacecontinues as the top portion of the layer on the grate, while the lowerpart of the layer, which is subjected to a less degree to the cokingheat, remains at the bottom of the layer and rests in contact with thegrate as the layerpasses to and is carried forward on said grate. I

The gaseous products of combustion arising from the burning of the fuelupon the chain grate rise into contact with the deflecting wall orpartition F and by the latter are deflected forward toward the front ofthe furnace and against the surface of the layer of coal resting uponthe said supporting plates I I I and thereafter pass upwardly around theforward edge of said arch or partition. The products of combustion beinghighly heated operate by their contact with the layer of coal resting onsaid inclined supporting surface to effect a preliminary heating orcoking operation by which the volatile constituents of coal are drivenoff, and the coal is prepared for burning off its less volatileconstituents as soon as it reaches the chain grate, through which air issupplied to effect combustion. The gaseous products of combustiondistilled from the coal on said inclined surface will be mixed with andignited by the highly heated products of combustion arising from theburning fuel on the grate, and with said highly heated products ofcombustion will be deflected forwardly and pass upwardly around thefront end of the dellecting arch or partition. In the case of bituminousorsemibitu1ninous coal the preliminary heating or coking operation willresult in a tendency to solidify the mass or layer resting upon-andtraveling downwardly over the plates I I I while the volatileconstituents are being distilled therefrom, or, in other words, tends toeffect a caking of the coal by the melting and running together of someof The caking of the coal or the cohesion of its particles to form asolid mass is, however, prevented through the disturbance or agitationthereof resulting from the movement downwardly over the transverseshoulders or ledges hereinbefore referred to and also by the shaking orvibratory movement given to the lower edges of said plates I I 1 so thatwhen the layer of coal reaches and is deposited upon the chain grate itis broken into fragments and is therefore prepared for the rapidcombustion thereof as soon as it reaches the chain grate; itsfragmentary condition permitting the free passage therethrough of airfor supporting con bustion.

In the modified construction of the inclined supporting surfaceillustrated in Figs. 3 to 7, said surface is formed by a plurality ofparallel, downwardly and rearwardly inclined, narrow plates or bars L LL supported at their upper ends upon a transverse horizontal pivot rod Land having their lower ends terminating adjacent to and above the topsurface of the chain grate D. The bars L are fixed or stationary, beingsupported in position by rigid arms 1 thereon which bear against ahorizontal, transverse girder L extending across the front of thefurnace below the feed hopper. The bars L and L which are arranged inalternation with the fixed bars L, are adapted to swing or oscillate attheir lower ends. The bars L have movement upwardly from the plane ofthe fixed bars L, while the bars L have movement downwardly from saidplane. Provision is made for giving vibratory movement to the lower endsof said bars L and L consisting of a horizontal rock-shaft M providedwith oppositely extending, rigid arms m m one for each of the bars L andL Each arm m is connected with one of the bars L by means of aconnecting rod M and each of the arms on is connected with one of thebars L by a connecting rod M With this construction, when the rockshaftM is rocked, alternate oscillatory movement is given to the two sets ofbars L L in such manner that the bars L rise above the bars L and the,bars L descend below said bars L, with the result of agitating the layerof fuel resting on the inclined surface formed by the several bars andthereby preventing the caking of the same,'without otherwise disturbingsaid layer, as before described, in the case of the construction shownin Figs. 1 and 2. The rock-shaft M may be given oscillatory movementfrom a rotative shaft N by means of an eccentric N on said shaft, and aneccentric rod N -which is pivotally connected with a block a, mounted ona rigid arm M affixed to one end of the rock-shaft M, said block a beingadjustably mounted on said arm M so as to provide for adjustment of theextent of rocking movement in the rockshaft.

In the performance of our novel process by the use of the furnaceconstructed as hereinbefore set forth, the layer of coal resting uponthe inclined supporting surface at the forward end of the furnace issubjected to a distilling or coking operation by which the volatileconstituents of the coal are driven off, and said volatile constituents,being immediately brought into contact or mixed with the highly heatedproducts of combustion which are deflected forwardly over the layer ofcoal on said inclined supporting surface by the deflecting arch orpartition, are entirely burned or consumed. The agitation to which saidlayer of coal resting upon the said inclined supporting surface issubjected, continuously breaks up the said layer during the process ofdistillation, so that it reaches the surface of the traveling chaingrate in a fragmentary condition, thereby permitting the free passage ofthe air therethrough to effect rapid and complete combustion thereof.After the lowerv layer of coal reaches the chain grate it movesrearwardly thereon without further disturbance of agitation untilcompletely consumed.

One important advantage arising from our novel process is that of theavoidance of formation of clinkers during the progress of combustion ofthe layer of fuel passing through the furnace. This result arises fromthe fact that there is no disturbance or agitation of the layer of fuel,when upon the inclined supporting surface or upon the chain grate, suchas would result in the lower part of the layer being brought to the topof such layer and subjected to the hi h heat within the interior of thefurnace. at will be understood in this connection that the formation ofclinkers usually arises from the lower parts of'the layer of fuelresting on a grate being brought to the top of said layer when nearlyconsumed or reduced to ashes, with the result that the incombustibleconstituents of the ashes are fused and clinkers are produced. In theprocess hereinbefore described, the layer of fresh fuel is broken upwhile being subjected to thepreliminary coking operation and before suchlayer of the fuel reaches the part of its path in which combustion takesplace, so that during the combustion period no further disturbance oragitation of the layer is re-.

quired in order to permit the free passage of air therethrough.Moreover, there is no mixing up or rolling over of the coal during thecoking period, such as would tend to the production of clinkers, itbeing manifest that if, during such coking period, the layer be notstirred up, but only broken or fractured, the surface portion thereof,which is first coked or prepared for combustion, will remain at the topof the layer during the combustion layer, w 10h is less nearly preparedfor combustion, will first receive the action of the airat the beginningof such combustion period. The cokingaction will have extended throughthe entire thickness of the'layer by the time the said layer reaches thepoint in its path when combustion begins and such layer will then bethoroughly prepared for combustion without the formation of clinkers,becaiise its lower ortion, which has been least subjected to the cokingoperation, will be more directly acted upon by the incoming air toeflect combustion thereof, while the upper part of the layer, havingbeen more thoroughly coked, will be in readiness for burning with therelatively smaller supply of oxygen which will reac Iperiod, while thelower part of said said upper part of the layer as the air passesthrough the same from below.

Another important advantage gained by our process is that of theincrease of igniting effect arising from the'better preparation of thefuel for ignition and complete combustion. This is due to the fact thatthe heated gaseous products of combustion from the entire layer of fuelare deflected forwardly part of the layer of burning fuel on the grateand there is therefore no more heat transmitted from the ignition archto the greater.

amount of incoming fresh fuel when the feed is rapid-than to the lesseramount of incoming'fresh coal when the feed is slow. Manifestly, in ourprocess the increase in the rate of feed will result in a largerquantity of fuel being burned upon the chain grate and the heatresulting from the combustion of such larger quantity of fuelwillproduce an increased heatin effect upon the incoming fuel substantia ycorresponding to the increase in the rate of feed. I

We claim as our invention 1. The process of burning coal which consistsin advancing the coal continuously into and through a furnace whenspread ina layer, first ap lying coking heat to the top surface of theayer without aeration thereof, to effect the coking of the coal, andimmediately after the completion of the coking operation admitting airto the bottom of the layer to effect combustion, agitating the part ofthe layer undergoing the coking operation to break up the layer andprevent caking or solidification of the coal; the agitation of the layerduring the coking operation and its subsequent advance movement duringcombustion being effected without stirring or mixing the coalconstituting the layer.

2. The process of burning coal which consists in advancing the coalcontinuously into and through a furnace when spread in a layer, firstcoking the coal without aeration and after the completion of the cokingoperation admitting air to the bottom of the layer to effect combustion,the coking being effected by directing the heated products of combustionarising from the portion of the layer undergoing combustion into contactwith the top surface of the portion of the layer undergoing the cokingoperation, and agitating the part of the layer undergoing the cokingoperation to break up the layer and prevent caking or solidification ofthe coal, the presence of two witnesses, this 2nd day of the agitationof the layer during the coking July A. D. 1907.

operation and its subse uent advance move- Y ment during combustioiibeing effected with- 5 out stirring or mixing the coal constituting thelayer. Witnesses:

In testimony, that We claim the foregoing A. M. BUNN,

as our invention we afiix our signatures in T. H ALFRED-S.

